Gas filled discharge tube



Feb. 12,- 1935. G. HOLST 1,991,279

GAS FILLED DISCHARGE TUBE Filed Oct. 17. 1931 I nuen for: Gilles mart,

f; ifa amz also of importance for other discharge tubes com I prising a gasfilling, for example, for "luminous I;

from the pinch 12, through which pass the lead I wires 13'j13 of'the being protected by wounding-same. The "anodes are separated by a Patented Feb.

TUB

Gilles H olst, Eindhoven,aNetherlands, assignor to :N. V. Philips Gloeilampenfabrieken, Eindhoven,

' Netherlands 1 Applicationoctober 17-, 1931,"Serial No. 569,488 Inthe NetherIands'October 31.1930 I ass. guest-215) 1 i This invention relates to a gasfllled discharge tube and more particularly toa rectifying tube having one or more anodesand an incandescent cathode. Besides for rectifiersihe invention is tubes known under the name neontubes.

In such gasiilled often suffers from discharge tubes the "cathode of the discharge path which ions are attracted by 2 the cathode. particularly ma This drawback makes itself 'ifes't when the cathode isan oxide, cathode and when a highten'sion is setup between the anodes and the cathodes.

phenomenon gives cathodeand to. ashortened life thereof. p According tofthefinvention this drawback is; obviated byfproviding anion catchenconstifl ore metal plates. disposed in tuted by one or m the vicinity of the incandescent cathode onfa side turned away from the anodes and extending parallel to the axis of the parallel, or almost cathode. 1

Due to the speed rise" to disintegration of the ably'an oxide cathode, is surrounded by. a-metal of theions in the vicinity of the cathode they tend to fly past the cathode thus colliding with are neutralized.

The invention is the metal plates where they particularly case of discharge tubes in which the cathode is surrounded by a metal sleeve. ion catcher is so designed that In this case the it extends-over some distance beyond the open ends of the sleeve.

In order to reach the cathode the ions comin from the anode must make a curve, since they must enter through the open ends of the sleeve. Instead of reaching the cathode the largest part of the ions will flash across'an'd strike the ion catcher.

This phenomenon may parting a suitable for which purpose be furthered by impotential to the ion catcher it is providedv with a lead wire.

A similar result may be obtained by electrically connecting the ion cathode, for example, through a resistance. In.

catcher to the incandescent this case the ion catcher, due to its large surface, will attract a large number of the ions moving towards the cathode.

The invention will be more construction thereof.

clearly understood accompanying drawing, repof example, some forms of Figure 1 is a perspective side view of a rectifier showing an embodiment of my invention as applied to'a multiple Fig. 2 is a perspe anode tube; ctive side View, partly in sec collisions of the positive'ions I the pinch 10, and I by tubes 11--'1l consisting, forexample; of "quartz.

efficacious in the sleeve.

tion, ofarectifier tube showing an embodiment of myinvention asapplied to a' single-anode anodes 3 are-supported from one end of the-tube anodes 3- 3,. the lead wires steatite tubes 14-14 surinstance; of nickel and is provided withfa lead wire-7- connected to the plate 4;-' i.

The filamentary cathode 2, which: is prefersleeve l5 which'passes through and :is secured to the r'nember 4. Thecathode is supported from its leads 8 and 9' areprotected The ion c'atcher5, which is located 'onathatsz side of the cathode-which is turned-away from I the-anodes. may have i if desired, an upstanding rim or may be cup-shaped.

My invention is especially well suited for rectifiers adapted for high voltages, in which case the ions in the vicinity of the cathode have a high speed, and their impact on the cathode is highly injurious to the cathode.

Fig. 2 shows a rectifier which has a single anode and in which the discharge path between the anode 3 and the cathode 2 is elongated in" a known manner by means of a sleeve 15 surrounding the cathode. The discharge may reach the cathode only through the open ends of this In this figure the parts shown also in Fig. 1 are designated by the same numerals.

The sealing-in of the pole Wires 8 and 9 is effected. in this case by means of two so-called sheath wires for each lead wire which carry together the current. The sleeve 15 and the ion catcher 6 are electrically and mechanically connected together and to the cathode 2 by means of a metal bushing 16 slipped on the lead wire 9 which bushing passes through the ion catcher and the sleeve 15 and is flanged at the upper side. The lead wire 8 passes at 1'7 freely through apertures provided in the sleeve and ion catcher. A second connection between the sleeve and the ion catcher is established at 18.

In both of the constructions described in order to reach the cathode the ions moving in the discharge path to the cathode must change their direction at the open ends of the sleeve 15. Since the ion catcher 6 is located below the sleeve part of the'discharge tube which Surroundsthe stem 20" from the remaining parts of thedischarge tube. At this place a space is formed into which the heat rays of the middle portion of the discharge tube penetrate with difliculty. The

obturation of such a space may be of importance when the discharge tube contains the vapour of a material of which also a quantity ina solid or liquid state is present in the tube, for instance,

in the form of a drop of mercury. The pressure within the tube depends on the temperature at the coolest part of the tube. space surrounding the stem 20 which is lesswarm thantherremaining part of thettube may.

servefor producing a-definite pressureimthe discharge tube.

While the-- drawingrepresents rectifiers of a definite type, various modifications arepossible without departing from theprinciple of the invention..

construction than! those shown-;and not, only a pluralityofanodes, but more than one 'incandescent 'cathodei may be used;

Furthermore -the invention, as stated-in the-- preamble; may also, be :usedin various other. gas-' filled tubes besidesthe rectifying tubesdescribed.

What I claim is:

1 A rectifier tube" having 1 an 7 envelope; a, gas-' eous filling; an incandesciblecathode; and an 8111a ode, .the axisof said pcathode being perpendicular to :the; discharge path-"between the cathode and theuanode; a metallic :membersurroundingsaid:

cathode, ands-intercepting the discharge path,.: and

a second :metallic member'disposedin the vicin' ity aoflthe icathode on its side; turnedaway ,fromv Consequently the,

The electrodes, for. instance, may be of different the anode, the two members being electrically connected with each other.

2. A rectifier tube having an envelope, a gaseous filling, an incandescible oxide cathode and an anode, an open-ended sleeve surrounding said cathode, and a metallic member disposed on the side of the cathode turned away from the anode and in close proximity to "said isleeve,= said metal member extending beyond the twoends of said sleeve.

3. A rectifier tube for high voltages comprising anenvelope a gaseous filling, an incandescible oxide cathode and an anode, said anode and cathode forminga discharge path between said anode and cathode, which is perpendicular to the axis of said-cathode, a sleeve concentrically surrounding the cathode and intercepting the discharge-path, said sleeve being open at the two ends, and a metal plate having a plane substan- 'tially parallel to the axis of the cathode and being. disposed-in the proximity .of said sleeve on :that side of-t-the cathode which is turned away from the anode.

4.1m electric discharge tube having an envelope, a gaseous filling, an anode and an incandescent cathode, a conductive member disposed between theanode and cathode and intercepting thedischarge path between said anode and cathodelsaid-member. substantially surrounding the cathode, and :a second conductive member disposed ,inltheuvicinitybf the cathode on its side turned away; from..the anode and. electrically connected with said cathode.

5. An electricdischarge. tube having an envelo'pe a gaseous filling, ,an incandescible cathode and a plurality of anodes, said anodes being 'disposedhonsone side ofisaid cathode, a metallic sleeve surroundingrthe cathode and intercepting the discharge paths -.between.the cathode and anodes, and.a secondmetallic member in the its side turned vicinity. ,of, the. cathode and on away from theanode'.

GILLES HOLST. 

